The present invention relates to lasers, and particularly to high-power flowing-gas lasers.
There has been considerable activity in recent years to produce high-power flowing-gas lasers for use particularly in the metalworking industries. Examples of some of the known lasers of this type are described in U.S. Pat. Nos. 3,641,457; 3,702,973; 3,886,481; 4,058,778; 4,317,090 and 4,321,558. One of the main problems in the design of such high-power lasers is the dissipation of the heat, since power lasers cannot operate efficiently at unduly high temperatures. For example, the CO.sub.2 laser, which is the one mainly used today for high power applications, cannot operate efficiently at temperatures much above 200.degree. C. While the heat dissipation, and therefore the power output, can both be increased by increasing the length of the laser channel, this entails a considerable increase in the size and cost of the laser.
One object of the present invention, therefore, is to provide a novel high-power flowing-gas laser which maximizes the length of the laser channel and of the power output capability of the laser for a given system size.
Another problem involved in the high-power flowing-gas lasers is optical distortion in the outputted beam arising from a number of causes. One is phase distortion due to a density gradient in the flowing gas and amplitude variation due to a gain gradient in the flowing gas both of which are described in the above-cited co-pending application Ser. No. 410,594 filed Aug, 23, 1982 now U.S. Pat. No. 4,486,887 and substantially reduced or eliminated by the systems described therein. I have found, however, that optical distortion is also caused by mechanical vibrational disturbances imparted to the optical system by the impeller and motor drive which produces the gas flow through the laser channel.
Accordingly, another object of the present invention is to provide a high-power flowing-gas laser which substantially reduces the latter optical distortion in the outputted laser beam.